Activated hepatic stellate cells (HSCs) have a central role as the main extracellular matrix (ECM) protein-producing cell during hepatic fibrogenesis. 1 Hepatic injury induces the HSCs to undergo a transdifferentiation or activation process, 1 which is characterized by loss of their intracellular vitamin A stores, 2 increase in proliferation, 3 changes in cellular morphology to a more myofibroblast-like cell type with expression of smooth muscle ␣-actin (␣-SMA), 4 and an increase in the production of ECM proteins, including type I collagen. 5 In addition, cultured HSCs express all 3 transforming growth factor ␤ (TGF-␤) isoforms 6,7 and TGF-␤ receptor types I, II, and III on the cell surface. 8 Treatment of HSCs in early culture with TGF-␤1 stimulates collagen type I messenger RNA (mRNA) expression 9,10 and protein synthesis, 10,11 inhibits HSC proliferation, 11-13 decreases the expression of matrix metalloproteinases, and increases the expression of tissue inhibitors of matrix metalloproteinases. 14 No change was observed in the level of ␣-SMA in TGF-␤1-treated HSCs. 15 Excessive TGF-␤ is associated with tissue damage caused by scarring in many diseases. 16 Clinical studies have revealed a close correlation between increased TGF-␤1 gene expression and the high expression of collagen type I mRNA in the liver tissue of patients with cirrhosis 17,18 and in experimental rat models of cirrhosis. 19,20 Furthermore, mRNA expression of TGF-␤1, TGF-␤2, and TGF-␤3 is increased in HSCs during fibrosis induced by bile duct ligation in rats. 21 Studies from transgenic mice support the etiologic and fibrogenic role for TGF-␤ in the development of liver fibrosis. Transgenic mice overexpressing mature TGF-␤1 under control of hepatocyte-specific promoters develop hepatic fibrosis with increased interstitial deposition of type I collagen. 22,23 Liver histology of an inducible transgenic mouse model overexpressing the active form of TGF-␤1 showed up-regulation of hepatic collagen type I and III mRNA and activation of HSCs. 24 TGF-␤ signals through its type I and type II receptors, which have serine/threonine kinase activity. The ligand binds to the constitutively active type II receptor, which then recruits and transphosphorylates type I receptor. 25 The activated type I receptor transiently associates with and phosphorylates Smad2 26 and Smad3, which then form heteromeric complexes with Smad4. [27][28][29] These complexes translocate to the nucleus, where the proteins function as transcriptional activators through their interaction with DNA-binding proteins. 30,31 Two inhibitory Smad proteins, Smad6 and Smad7, block Smad-mediated signaling in cells. [32][33][34] To date, Smad proteins are the only TGF-␤ receptor substrates with a demonstrated ability to propagate signals. 35 Several other signaling molecules and pathways are also activated by TGF-␤, including TGF-␤-activated kinase 1 (TAK1) 36 and the mito-

DILI appears to be a highly relevant health problem in Korea. "Herbal medications" are the principal cause of DILI. A more objective and reproducible causality assessment tool is strongly desired as the RUCAM scale frequently undercounts the cases caused by herbs owing to a lack of previous information and incompatible time criteria.

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Exosomal noncoding RNAs (ncRNAs) have unique expression profiles reflecting the characteristics of a tumor, and their role in tumor progression and metastasis is emerging. However, the significance of circulating exosomal ncRNAs in the prognosis of hepatocellular carcinoma (HCC) remains to be elucidated. We therefore determined the prognostic significance of circulating exosomal ncRNAs (miRNA-21 and lncRNA-ATB) for human HCC. This prospective study enrolled 79 HCC patients between October 2014 and September 2015. Exosomes were extracted from serum samples using the ExoQuick Exosome Precipitation Solution. To validate the isolation of the exosomes from serum, immunoblotting for exosome markers and characterization of nanoparticle using NanoSight were performed. NcRNAs were isolated from exosomes using the miRNeasy serum/plasma micro kit. Both circulating exosomal miRNA-21 and lncRNA-ATB were related to TNM stage and other prognostic factors, including the T stage and portal vein thrombosis. Multivariate analysis using the Cox regression test identified that both higher miRNA-21 and higher lncRNA-ATB were independent predictors of mortality and disease progression, along with larger tumor size and higher C-reactive protein (all p < 0.05). The overall survival and progression-free survival were significantly lower in patients with higher circulating levels of exosomal miRNA-21 (≥0.09) and lncRNA-ATB (≥0.0016) (log-rank test: p < 0.05). In conclusion, our study has provided strong evidence that circulating exosomal ncRNAs (miRNA-21 and lncRNA-ATB) are novel prognostic markers and therapeutic targets for HCC.

Activated hepatic stellate cells (HSCs) are the main producers of extracellular matrix in the fibrotic liver and contribute to hepatic inflammation through the secretion of chemokines and the recruitment of leukocytes. This study assesses the function of CD40 on human HSCs. Activated human HSCs express CD40 in culture and in fibrotic liver, as determined by flow cytometry, RT-PCR, and immunohistochemistry. CD40 expression is strongly enhanced by IFN-γ. Stimulation of CD40 with CD40 ligand (CD40L)-transfected baby hamster kidney cells induces NF-κB, as demonstrated by the activation of I-κB kinase (IKK), increased NF-κB DNA binding, and p65 nuclear translocation. CD40-activated IKK also phosphorylates a GST-p65 substrate at serine 536 in the transactivation domain 1. Concomitant with the activation of IKK, CD40L-transfected baby hamster kidney cell treatment strongly activates c-Jun N-terminal kinase. CD40 activation increases the secretion of IL-8 and monocyte chemoattractant protein-1 by HSCs 10- and 2-fold, respectively. Adenovirally delivered dominant negative (dn) IKK2 and TNFR-associated factor 2dn inhibit IKK-mediated GST-I-κB and GST-p65 phosphorylation, NF-κB binding, and IL-8 secretion, whereas IKK1dn and NF-κB-inducing kinase dominant negative do not have inhibitory effects. We conclude that the CD40-CD40L receptor-ligand pair is involved in a cross-talk between HSCs and immune effector cells that contributes to the perpetuation of HSC activation in liver fibrosis through TNFR-associated factor 2- and IKK2-dependent pathways.